1. Field of the Invention
This invention relates to switch assemblies used especially but not exclusively in machinery guards enclosing kinetic machinery.
2. Description of Related Art
Known switch assemblies comprise a switch adapted to be fitted to an enclosure and an actuator adapted to be fitted to a door, gate or protective cover of the enclosure and insertable into the switch. When the enclosure is closed by the door, gate or protective cover, the actuator is inserted into the switch which enables the energisation of a machine within the enclosure as the result of the switch turning on an electrical power supply.
Switches of this type have a housing in which are situated normally-open contacts, one set fixed, the other movable and carried by an axially-movable push rod spring-loaded to maintain the sets of contacts apart and the power supply consequently OFF.
The axially-movable push rod bears against a rotatable, can of a cam arrangement normally disposed to secure the push rod in a power supply OFF position but which is operable by the actuator to cause cam rotation and axial movement of the push rod to a power supply ON position.